Avoiding the dreaded Spam folder when sending e-mail

Modified on Sat, 28 Jul 2018 at 03:00 PM

As a business communicating with your clients using e-mail, you are under the constant pressure of having to think about spam traps, spam trigger words, and anti-spam laws. Crafting targeted emails so as to avoid being sent to spam, or being marked as spam by your subscribers has become an art in itself. Why?

Because Internet Service Providers (ISPs) are waging a brutal, yet justified war against spammers. Unfortunately, the victims are not always just the spammers. Collateral damage happens to include some of us, the good-willed email senders who simply don’t have the luck or enough experience.

According to research conducted by ReturnPath, only 79% of emails sent by genuine email marketers reach subscribers’ inboxes. How come? Well, only a small error is enough to send an email from an honest email send like yourself to the 9th circle of email inbox hell, causing serious, almost irreparable damage to email deliverability and the sender reputation.

The seriousness of the issue is evident from the very fact that almost every internet major country has lawfully restricted the use of email spam. The American CAN-SPAM Act of 2004 and Canadian CASL of 2014 (Canada’s Anti-Spam Legislation) represent the leading states’ attempts to protect people from unsolicited, and unrequested bulk mail. Along with the ISPs, they seem to be doing a good job.

So, I would like to present the dos and don’ts of targeted email marketing. This comprehensive guide will help you navigate around spam traps and filters to securely arrive at the desired inbox.

What is Spam traps and Spam filters
ISP’s first line of defense against spammers are spam traps. They are actually email addresses designed specifically for identifying and tracking spammers.

If your triggered email hits such an address, you are immediately flagged as a spammer by the ISP. Your IP address and your ‘from domain’ get blocked, your deliverability rates plummet, and it can take you up to a year to restore a good sender reputation. This is how pure spam traps function. Pretty scary!

Another thing to worry about are recycled spam traps. They are inactive email addresses that ISP acquires after a certain period of inactivity. If your email hits such an address, the consequences are not as serious. Either your ESP or the ESP of your client will send you a notification of the bounce to let you know you are emailing a dormant address. But, if you continue to send emails to hard bounces, the ISP will eventually record it as a spam trap hit.

ISP’s second line of defence against spammers are spam filters, a program that, by using different criteria, filters out unwanted and unsolicited bulk mail, thus preventing it from ever reaching email inboxes. Spam traps scrutinise your emails to the minutest details so as to make sure irrelevant and poorly written content never reaches the subscribers.

So here are some tips on how to avoid having your e-mails marked as 'spam':

Take good care of the subject lines

As the old proverb states and a Placebo song, the devil is in the details. This applies to the art of email sending in general, especially when it comes to crafting subject lines.


In the etiquette of email communication or any Internet communication, using upper case to write words and sentences is usually seen as shouting, and is considered rude and disrespectful. So avoid using all capital letters in the subject lines.

In the research conducted by the Radicati Group, the majority of the people surveyed, 85%, showed preference of an all lowercase subject line.

Subject lines written in uppercase will not only annoy the receivers, who will feel tempted to mark your email as spam, but it will also alert spam filters.

Don’t use multiple exclamation points

In order to draw people’s attention to your email, it is important to craft a witty, inquisitive subject lines, and a relevant, short email.

As a matter of fact, the research shows that email subject lines that end with a question mark have 44% higher open rates than those that contain exclamation points.  Don’t create drama and sensation by using multiple exclamation points in a row because the chances are they will come across as spammy to the receivers, and to the ISPs.

Stay away from spam trigger words

Spam trigger words - words that considered span in email

To avoid hitting spam filters and getting caught in them, pay attention to the wording of your subject lines.

Certain words and phrases, such as ‘free’, ‘best price’, ‘cash’, ‘no obligation’ have been blacklisted owing to their association with the spam mail. Recall all those emails we used to get that offered a free prize in the subject line in return for following a couple of steps of which you learn once you open the email.

Spam trigger words were usually collected from emails such as these, and should be avoided.

Ultimately, HubSpot offers these as examples of the good subject lines:

“Hi [name], [question]?”

“Did you get what you were looking for?”

“You are not alone.”

“Feeling blue? Like puppies?”

Don’t make false promises

In order to avoid being marked as spam, it is important to align the subject line with what you offer in the email. In other words, avoid writing spammy emails described in the paragraph above.

If your subject line states: “Hello Jovana, a quick question?”, then indeed do include a short question easy to answer to. Deliver on what you promise in the subject line. Because, if your email copy doesn’t correspond with the offer in the subject line, it is more likely people will mark your email as spam.

Take good care of the email body

Spam filters rigorously scrutinize your copy as well. ISPs go as far as to mark emails as spam based on the specific content or images.

Everything matters, the design, the fonts, the attachments, the embeds, the images, everything. Even the most bizarre things, such as using the word ‘viagra’, can alert the spam filters. The devil is in the details, and here, the best policy is to keep the details to the minimum and to simplify, as much as possible.

Here are some tips on how to craft an email copy that’ll bypass the spam filters and appeal to your subscribers:

Avoid rich media content

A majority of email clients don’t allow the ability to view rich media content, such as video embeds and Flash, so avoid putting them in your emails.

If you do insert them, and they don’t show or work properly, it will seem sloppy and messy to your clients. This can damage your credibility as the email will seem spammy.

If the media content is essential to your marketing campaign, put it on your website and insert a link to it in your copy. For example, if you want the subscribers to see a video, include an image with a play button that, once clicked, will lead your clients to the particular video on your website.

Also, avoid using JavaScript and other dynamic scripts, as they will alert the spam filters.

Your clients usually don’t allow the dynamic scripts to function, so using them will create pretty much the same effect as the media content that doesn’t show properly.

Avoid embedding forms

Embedding forms in your email copy represent another red flag to the spam filters. Forms represent a security risk and aren’t usually supported across common email clients.

Instead of including embedded forms, you can either link to the page you wish them to visit, or insert a call-to-action button.

Avoid including attachments

Attaching files to your emails, like Word documents or PDFs, alerts spam filters immediately. Attached files also increase the size of your email, so consequentially, it takes them longer to load.

You can bypass this by placing the particular document on your website and providing a link, or a CTA that leads to the document’s location.

Tone down the fonts and colours

People seem to pay a lot of attention to the fonts and colours used in the copy. In the previously mentioned Radicati Group study, over 60% of the people surveyed found it unacceptable if the email marketers used irregular fonts, different font sizes and font colours. And over 70% of people declared that they prefer one size fonts.

Irregular font colours and sizes also alert spam filters, and the same goes for invisible text (white font on the white background for example). So simplify!

Cut back on the images

Even though we live in an era where pictures and images dominate all spheres of life, it seems that in email marketing you can have one too many.

Including a lot of images, or big images will increase the load time of your email, which can affect deliverability rates.

Making your copy in the form of one big image will also probably get it stuck in spam. For example, Microsoft Outlook doesn’t recognize background images so an email like this will probably not be displayed correctly:

To avoid this, make sure to include images that are relevant to the content and complement it. Resize the images if necessary, but take special care not to damage their visual integrity. And always, always, host your images at credible services.

Make sure your images display correctly

Some email users allow the display of images while others block images altogether. Your images won’t show correctly to the users who block images, which will make your email seem spammy, messy and sloppy.

To avoid that don’t miss to add intelligible, unambiguous alt text in your image. This is how alt-text looks like

Alt text can be easily edited and can also be added with custom variables as apparent in the above image.

Correct spelling and grammar

Spell-checking and proofreading are essential components of every good email marketing campaign. Incorrect spelling and faulty grammar will damage your credibility with your clients and make you seem unprofessional.

These errors are also major spam triggers. So do take the time to edit and proofread.

Take care of the follow-up

Never send emails just to send them. Try to offer valuable, engaging and relevant content because this is probably the only way to avoid being marked as spam.

A steady flow of communication is important if you are following up with your clients or if you are trying to re-engage the inactive ones.

Instead of opting for massive blasts (that tend to reek of spam) that you send from time to time, try to space them evenly, after shorter periods of time, just to remind your clients that you are there.

This way, you will have a firmer grasp on the inactive ones, preventing them from cluttering your email list or becoming possible spam traps. And the active ones will appreciate your effort and value.


Unfortunately, there is no magic formula that guarantees your emails won’t land in spam. ISPs, ESPs and anti-spam laws are brutal, and there is no definite guide to help you deal with the deliverability issues.

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